This session invites papers in the memory of the Christian Blodau,on the theoretical, empirical, and simulation of the biogeochemistry of peatlands and lakes especially on the processes involved in the production and fate of dissolved organic matter (DOM); the redox chemistry and electron transfers in the storage and turnover of carbon, nitrogen and sulphur; and the production and emission of methane (CH4) and carbon dioxide (CO2) from peatlands under pristine and stressed conditions (climate and land-use change); groundwater – lake/peatland interactions and its role in the acid chemistry; and the fate of contaminants in peat and lake sediments. Theoretical, observational, experimental and simulation studies, particular those that combine approaches are encouraged.